Vibration Controller Design for Confined Masonry Walls by Distributed Genetic Algorithms

• Published in: Journal of structural engineering (New York, N.Y.) Vol. 134; no. 2; pp. 300 - 309
• Main Authors: Joghataie, Abdolreza, Mohebbi Asbmarz, Mohtasham
• Format: Journal Article
• Language: English
• Published: American Society of Civil Engineers 01.02.2008
• Subjects: TECHNICAL PAPERS
• ISSN: 0733-9445; 1943-541X
• DOI: 10.1061/(ASCE)0733-9445(2008)134:2(300)

Active control of confined masonry walls with nonlinear hysteretic response has been studied through numerical simulation in this paper. The objective has been to reduce the response to below the failure level when the walls have been subjected to earthquakes. An active tendon control mechanism, comprised of prestressed tendons and an actuator, has been used. A nonlinear control algorithm has also been developed based on Wilson’s- θ instantaneous linear optimal control method and applied. To achieve the best results, weights in the performance index corresponding to displacement, velocity, acceleration, and control force have been optimized by distributed genetic algorithms. An illustrative example has been included where, for designing and testing the controller, a series of white noise ground accelerations of different amplitudes as well as a number of strong earthquakes, such as Chi Chi in 1999 and Northridge in 1994, have been used. Some practical aspects such as actuator-wall interaction, actuator saturation, sensor saturation, and time delay have not been considered in this phase of the study. The designed controllers have been clearly successful in all the tests, even for earthquakes of very high intensity.